As a negative electrode material for lithium-ion batteries,silicon monoxide(SiO)suffers from dramatic volume changes during cycling,causing excessive stress within the electrode and resulting in electrode deformation ...As a negative electrode material for lithium-ion batteries,silicon monoxide(SiO)suffers from dramatic volume changes during cycling,causing excessive stress within the electrode and resulting in electrode deformation and fragmentation.This ultimately leads to a decrease in cell capacity.The trends of volume expansion and capacity change of the SiO/graphite(SiO/C)composite electrode during cycling were investigated via in situ expansion monitoring.First,a series of expansion test schemes were designed,and the linear relationship between negative electrode expansion and cell capacity degradation was quantitatively analyzed.Then,the effects of different initial pressures on the long-term cycling performance of the cell were evaluated.Finally,the mechanism of their effects was analyzed by scanning electron microscope.The results show that after 50 cycles,the cell capacity decreases from 2.556 mAh to 1.689 mAh,with a capacity retention ratio(CRR)of only 66.08%.A linear relationship between the capacity retention ratio and thickness expansion was found.Electrochemical measurements and scanning electron microscope images demonstrate that intense stress inhibits the lithiation of the negative electrode and that the electrode is more susceptible to irreversible damage during cycling.Overall,these results reveal the relationship between the cycling performance of SiO and the internal pressure of the electrode from a macroscopic point of view,which provides some reference for the application of SiO/C composite electrodes in lithium-ion batteries.展开更多
Silicon monoxide(SiO)is highly attractive as an anode material for high-energy lithium-ion batteries(LIBs)due to its significantly higher specific capacity.However,its practical application is hindered by substantial ...Silicon monoxide(SiO)is highly attractive as an anode material for high-energy lithium-ion batteries(LIBs)due to its significantly higher specific capacity.However,its practical application is hindered by substantial volume expansion during cycling,which leads to material pulverization and an unstable solid electrolyte interphase(SEI)layer.Inspired by the natural root fixation in soil,we designed a root-like topological structure binder,cassava starch-citric acid(CS-CA),based on the synergistic action of covalent and hydrogen bonds.The abundant-OH and-COOH groups in CS-CA molecules effectively form hydrogen bonds with the-OH groups on the SiO surface,significantly enhancing the interfacial interaction between CS-CA and SiO.The root-like topological structure of CS-CA with a high tolerance alleviates the mechanical stress generated by the volume changes of SiO.More encouragingly,the hydrogen bond action among CS-CA molecules produces a self-healing effect,which is advantageous for repairing damaged electrodes and preserving their structural integrity.As such,the CS-CA/SiO electrode exhibits exceptional cycling performance(963.1 mA h g^(-1)after 400 cycles at 2 A g^(-1))and rate capability(558.9 mA h g^(-1)at 5 A g^(-1)).This innovative,topologically interconnected,root-inspired binder will greatly advance the practical application of long-lasting micron-sized SiO anodes.展开更多
The design of advanced binders plays a critical role in stabilizing the cycling performance of large-volume-effect silicon monoxide(SiO)anodes.For the classic polyacrylic acid(PAA)binder,the self-association of-COOH g...The design of advanced binders plays a critical role in stabilizing the cycling performance of large-volume-effect silicon monoxide(SiO)anodes.For the classic polyacrylic acid(PAA)binder,the self-association of-COOH groups in PAA leads to the formation of intramolecular and intermolecular hydrogen bonds,greatly weakening the bonding force of the binder to SiO surface.However,strengthening the binder-material interaction from the perspective of binder molecular regulation poses a significant challenge.Herein,a modified PAA-Li_(x)(0.25≤x≤1)binder with prominent mechanical properties and adhesion strength is specifically synthesized for SiO anodes by quantitatively substituting the carboxylic hydrogen with lithium.The appropriate lithium substitution(x=0.25)not only effectively increases the number of hydrogen bonds between the PAA binder and SiO surface owing to charge repulsion effect between ions,but also guarantees moderate entanglement between PAA-Li_x molecular chains through the ion-dipole interaction.As such,the PAA-Li_(0.25)/SiO electrode exhibits exceptional mechanical properties and the lowest volume change,as well as the optimum cycling(1237.3 mA h g^(-1)after 100cycles at 0.1 C)and rate performance(1000.6 mA h g^(-1)at 1 C),significantly outperforming the electrode using pristine PAA binder.This work paves the way for quantitative regulation of binders at the molecular level.展开更多
Progress in the fast charging of high-capacity silicon monoxide(SiO)-based anode is currently hindered by insufficient conductivity and notable volume expansion.The construction of an interface conductive network effe...Progress in the fast charging of high-capacity silicon monoxide(SiO)-based anode is currently hindered by insufficient conductivity and notable volume expansion.The construction of an interface conductive network effectively addresses the aforementioned problems;however,the impact of its quality on lithium-ion transfer and structure durability is yet to be explored.Herein,the influence of an interface conductive network on ionic transport and mechanical stability under fast charging is explored for the first time.2D modeling simulation and Cryo-transmission electron microscopy precisely reveal the mitigation of interface polarization owing to a higher fraction of conductive inorganic species formation in bilayer solid electrolyte interphase is mainly responsible for a linear decrease in ionic diffusion energy barrier.Furthermore,atomic force microscopy and Raman shift exhibit substantial stress dissipation generated by a complete conductive network,which is critical to the linear reduction of electrode residual stress.This study provides insights into the rational design of optimized interface SiO-based anodes with reinforced fast-charging performance.展开更多
基金supported by the Fundamental Research Funds for the Central Universities(WK2090000055)Anhui Provincial Natural Science Foundation of China(2308085QG231).
文摘As a negative electrode material for lithium-ion batteries,silicon monoxide(SiO)suffers from dramatic volume changes during cycling,causing excessive stress within the electrode and resulting in electrode deformation and fragmentation.This ultimately leads to a decrease in cell capacity.The trends of volume expansion and capacity change of the SiO/graphite(SiO/C)composite electrode during cycling were investigated via in situ expansion monitoring.First,a series of expansion test schemes were designed,and the linear relationship between negative electrode expansion and cell capacity degradation was quantitatively analyzed.Then,the effects of different initial pressures on the long-term cycling performance of the cell were evaluated.Finally,the mechanism of their effects was analyzed by scanning electron microscope.The results show that after 50 cycles,the cell capacity decreases from 2.556 mAh to 1.689 mAh,with a capacity retention ratio(CRR)of only 66.08%.A linear relationship between the capacity retention ratio and thickness expansion was found.Electrochemical measurements and scanning electron microscope images demonstrate that intense stress inhibits the lithiation of the negative electrode and that the electrode is more susceptible to irreversible damage during cycling.Overall,these results reveal the relationship between the cycling performance of SiO and the internal pressure of the electrode from a macroscopic point of view,which provides some reference for the application of SiO/C composite electrodes in lithium-ion batteries.
基金supported by the National Natural Science Foundation of China(Grant Nos.22378342,92372101,52162036,and 21875155)the Fundamental Research Funds for the Central Universities(20720220010)+3 种基金the National Key Research and Development Program of China(2021YFA1201502)the Natural Science Foundation of Sichuan Province(Grant No.2024NSFSC1160)the Postdoctoral Fellowship Program of CPSF(Grant No.GZB20230608)support of Nanqiang Young Top-notch Talent Fellowship in Xiamen University。
文摘Silicon monoxide(SiO)is highly attractive as an anode material for high-energy lithium-ion batteries(LIBs)due to its significantly higher specific capacity.However,its practical application is hindered by substantial volume expansion during cycling,which leads to material pulverization and an unstable solid electrolyte interphase(SEI)layer.Inspired by the natural root fixation in soil,we designed a root-like topological structure binder,cassava starch-citric acid(CS-CA),based on the synergistic action of covalent and hydrogen bonds.The abundant-OH and-COOH groups in CS-CA molecules effectively form hydrogen bonds with the-OH groups on the SiO surface,significantly enhancing the interfacial interaction between CS-CA and SiO.The root-like topological structure of CS-CA with a high tolerance alleviates the mechanical stress generated by the volume changes of SiO.More encouragingly,the hydrogen bond action among CS-CA molecules produces a self-healing effect,which is advantageous for repairing damaged electrodes and preserving their structural integrity.As such,the CS-CA/SiO electrode exhibits exceptional cycling performance(963.1 mA h g^(-1)after 400 cycles at 2 A g^(-1))and rate capability(558.9 mA h g^(-1)at 5 A g^(-1)).This innovative,topologically interconnected,root-inspired binder will greatly advance the practical application of long-lasting micron-sized SiO anodes.
基金supported by the National Natural Science Foundation of China (Grant Nos.92372101,52162036 and 21875155)the Fundamental Research Funds for the Central Universities (Grant Nos.20720220010)the National Key Research and Development Program of China (Grant Nos.2021YFA1201502)。
文摘The design of advanced binders plays a critical role in stabilizing the cycling performance of large-volume-effect silicon monoxide(SiO)anodes.For the classic polyacrylic acid(PAA)binder,the self-association of-COOH groups in PAA leads to the formation of intramolecular and intermolecular hydrogen bonds,greatly weakening the bonding force of the binder to SiO surface.However,strengthening the binder-material interaction from the perspective of binder molecular regulation poses a significant challenge.Herein,a modified PAA-Li_(x)(0.25≤x≤1)binder with prominent mechanical properties and adhesion strength is specifically synthesized for SiO anodes by quantitatively substituting the carboxylic hydrogen with lithium.The appropriate lithium substitution(x=0.25)not only effectively increases the number of hydrogen bonds between the PAA binder and SiO surface owing to charge repulsion effect between ions,but also guarantees moderate entanglement between PAA-Li_x molecular chains through the ion-dipole interaction.As such,the PAA-Li_(0.25)/SiO electrode exhibits exceptional mechanical properties and the lowest volume change,as well as the optimum cycling(1237.3 mA h g^(-1)after 100cycles at 0.1 C)and rate performance(1000.6 mA h g^(-1)at 1 C),significantly outperforming the electrode using pristine PAA binder.This work paves the way for quantitative regulation of binders at the molecular level.
基金the National Natural Science Foundation of China(Nos.22209095 and 22238004).
文摘Progress in the fast charging of high-capacity silicon monoxide(SiO)-based anode is currently hindered by insufficient conductivity and notable volume expansion.The construction of an interface conductive network effectively addresses the aforementioned problems;however,the impact of its quality on lithium-ion transfer and structure durability is yet to be explored.Herein,the influence of an interface conductive network on ionic transport and mechanical stability under fast charging is explored for the first time.2D modeling simulation and Cryo-transmission electron microscopy precisely reveal the mitigation of interface polarization owing to a higher fraction of conductive inorganic species formation in bilayer solid electrolyte interphase is mainly responsible for a linear decrease in ionic diffusion energy barrier.Furthermore,atomic force microscopy and Raman shift exhibit substantial stress dissipation generated by a complete conductive network,which is critical to the linear reduction of electrode residual stress.This study provides insights into the rational design of optimized interface SiO-based anodes with reinforced fast-charging performance.
